PLAN´TAR, _a._ Pertaining to the sole. A certain muscle is the
_plantaris_.
PLAN´TIGRADE, _a._ Walking on the back of the tarsus as well as on the
soles of the toes. Many pygopodous birds are plantigrade.
PLAS´MA, _n._ Colorless fluid of the blood.
PLAS´TIC, _a._ That may be moulded. Forming or serving to form;
_histogenetic_. _Plastic force._ See NISUS FORMATIVUS.
PLEU´RA, _n._ Membrane lining the thorax and investing the lungs.
PLEURAPOPH´YSIS, _n._ Segment of the hæmal arch next to the centrum. The
vertebral rib of a bird is a _pleurapophysis_.
PLEX´US, _n._ Union in network of nerves, vessels, or fibres. Said
especially of the anastomosis of nerves.
PLI´CA ALA´RIS, or PLI´CA PREALA´RIS, _n._ The feathered fold of skin
on the front border of the wing stretched by an elastic tendon from the
shoulder to the wrist, rendering the smooth straight anterior border of
the wing. (_Plica alaris_ is rarely used for the fold or bend of the
wing.)
PLI´CA INTERDIGITA´LIS, _n._ Webbing between the toes. Same as _palama_.
PLI´CÆ PRIMITI´VÆ, _n. pl._ Primitive folds; certain parallel lines
observed in the early embryonal trace.
PLU´MA, _n._ A feather in general. Compare PENNA and PLUMULA. (1.)
A feather of which the two webs are equal and alike is called
_isopogonous_: otherwise _anisopogonous_.
PLU´MAGE, _n._ The feathers, collectively; PTILOSIS (which see).
PLUM´BEOUS, _a._ Having the color of tarnished lead; dull bluish-gray.
PLUM´IPED, _a._ Having the feet feathered.
PLU´MOSE, PLU´MOUS, _a._ Feathery; in general, having feathers;
feathered. Compare PENNACEOUS and PLUMULACEOUS.
PLU´MULA, _n._ A down feather, lacking certain qualities and parts of a
_penna_.
PLUMULA´CEOUS, _n._ Downy. Compare PENNACEOUS.
PNEUMAT´IC, _a._ Relating to the respiratory system; permeated with air.
PNEUMOGAS´TRIC, _a._ Pertaining to lungs and belly; a name of the most
extensive cranial nerve.
PODARTH´RUM, _n._ Foot-joint; the articulation of the toes collectively
with the metatarsus. (100.)
PO´DIUM, _n._ Foot. (Same as _pes_.) Generally used, however, for the
_toes_ collectively without the shank. (112.)